It is a natural resin that is obtained from a tropical plant. It is usually yellowish-brown in colour and soluble in ethyl alcohol, ethers of petroleum, chloroform and oil of turpentine. Among many balsams utilized in the course of time in painting (Balsam of Peru, of Mecca, Balsam of Canada), the copaiva balsam is the only one that still finds use today as a dilutent for oil paints and varnishes, in substitution for oil of turpentine. In restoration, it was used in the Pettenkofer regeneration process as an additive for solvents for the removal of superficial varnishes. |